Bank Account question

[Rick LaFleur]

I am close to finishing refreshing STR and putting on AirBNB for the first time.  This townhome was purchased as primary, then kept after buying another home as primary, so it is held personally, not in LLC.  Is there a legal need to use business checking to house income and pay expenses even if not in LLC? I know that it is better for obvious tracking means, but am curious about whether it is required for tax purposes.

Thanks.